JP6707674B2 - Scroll compressor - Google Patents

Description

The present invention relates to scroll compressors.

2. Description of the Related Art Conventionally, scroll compressors integrated with motors have been widely used. In a motor-integrated scroll compressor, a cooling fan is generally attached to a motor rotating shaft in order to cool a compression unit that becomes hot during operation.

Electrolytic corrosion of bearings has become a problem in motors that drive compressors. For example, when a motor is operated at a variable speed using an inverter power supply, the shaft voltage generated on the rotating shaft tends to cause electrolytic corrosion of the bearing. The occurrence of electrolytic corrosion of the bearing causes adverse effects such as shortening of the life of the bearing. Therefore, in order to prevent this, it is required to reduce the shaft voltage of the motor.

For example, in Patent Document 1, the axial voltage of the motor is reduced by bringing the brush in the brush holder attached to the fan cover into contact with the end surface of the radial fan provided at the axial end portion of the end bracket. A gap type permanent magnet synchronous motor is disclosed.

JP, 2005-50798, A

In the configuration described in Patent Document 1, in order to electrically couple the brush in contact with the radial fan to the ground potential, it is necessary to electrically connect the fan cover with the brush holder to the case housing. For this reason, the entire size tends to increase due to the design.

Therefore, an object of the present invention is to provide a scroll compressor capable of reducing the axial voltage and saving space.

As a preferred embodiment of the scroll compressor according to the present invention, a rotor housed in a motor casing, a stator housed in the motor casing to drive the rotor to rotate, and a stator held by a bearing to be integrated with the rotor. A rotary shaft that rotates around, an end bracket that penetrates one end of the rotary shaft and closes the motor casing, and a second end that supports the other end of the rotary shaft, and a swirl motion that rotates by the rotation of the rotary shaft. A scroll, a fixed scroll arranged to face the orbiting scroll, and the end bracket are fixed to one end of the rotary shaft with a space therebetween, and are fixed to one end of the rotary blade housed inside the fan cover. A suction-type cooling fan that sucks outside air from a suction port provided on an end surface of the fan cover facing the end bracket by rotation and generates cooling air for cooling the fixed scroll or the orbiting scroll inside the fan cover. And a static elimination brush fixed to the end bracket facing the cooling fan and having one end in contact with the rotation shaft.

According to the present invention, it is possible to realize a scroll compressor capable of reducing the axial voltage and saving space.

It is sectional drawing which looked at the scroll compressor 100 concerning an example from the side. It is a figure which expands and shows the stator 31 and rotor 32 of the motor 10 shown in FIG. It is a side view of the scroll compressor 100 which concerns on an Example.

FIG. 1 shows a cross-sectional view of a scroll compressor 100 according to the embodiment as seen from a side surface. The scroll compressor 100 includes a motor 10 and a compression unit 110 driven by the motor 10. In the following description, an example of the configuration when an axial gap type motor is applied as the motor 10 will be described.

In the motor casing 14 of the motor 10, a disc-shaped stator 31 is arranged so as to be sandwiched between a pair of disc-shaped rotors 32. The motor casing 14 is made of a metal such as Al and has a cylindrical shape having openings at both ends. A flange 15 made of metal is provided in the opening of the motor casing 14 on the side of the compression unit 110, and an end bracket 16 made of metal is provided in the opening on the side opposite to this opening, and both openings are provided. Is closed.

The rotating shaft 12 is provided so as to penetrate the central portions of the stator 31 and the rotor 32. The rotating shaft 12 is rotatably supported by a main bearing 33 provided on the compression unit 110 side and an anti-load bearing 34 provided on the opposite side of the main bearing 33 with the stator 31 interposed therebetween. The main bearing 33 is held by the flange 15, and the anti-load bearing 34 is held by the end bracket 16. The rotary shaft 12 has an eccentric portion 12a at the end on the main bearing 33 side.

An end portion of the rotating shaft 12 on the side opposite to the anti-load bearing 34 penetrates the end bracket 16, and a cooling fan 13 is installed on the end portion side. The cooling fan 13 is configured such that a rotary blade 131 mounted on the rotary shaft 12 is housed in a resin fan cover 132. A counter weight 135 is provided between the rotary blade 131 and the fan cover 132 at the end of the rotary shaft 12.

The cooling fan 13 is provided at a predetermined distance D from the end bracket 16 in order to secure a space 20 for intake.

The distance D is determined by the surface 161 of the end bracket 16 that faces the cooling fan 13 (hereinafter, simply referred to as the surface 161 of the end bracket 16) and the end surface 132A of the fan cover 132 that faces the end bracket 16 (hereinafter, simply fan cover). End surface 132A of 132).

The cooling fan 13 sucks the outside air flowing into the space 20 from the side surface of the cooling fan by the rotation of the rotary blades 131 driven by the rotating shaft 12 through a suction hole (not shown) provided in the end surface 132A to cool the cooling air. This is a so-called suction type cooling fan that generates

Most of the outside air around the cooling fan 13 that has flowed into the space 20 is sucked into the cooling fan 13 through the suction port on the outer diameter side of the cooling fan 13. The cooling air generated inside the fan cover 132 by the rotation of the rotary blades 131 is supplied to the fixed scroll 43 or the orbiting scroll 44 of the compression unit 110, which will be described later, through a duct (not shown).

A gap is formed between the stator 31 and the rotor 32. As a result, the stator 31 and the rotor 32 are housed in the motor casing 14 in a state of being opposed to each other with a gap therebetween in a direction parallel to the rotating shaft 12.

FIG. 2 shows an enlarged view of the stator 31 and the rotor 32 of the motor 10 shown in FIG. The rotor 32 includes a yoke (not shown) made of a magnetic material and a permanent magnet 321 arranged in the circumferential direction and connected to the yoke.

The stator 31 includes a plurality of iron core pieces 311 arranged at equal intervals in the circumferential direction. A coil 312 is wound around the iron core piece 311 via a non-magnetic material. The iron core pieces 311 arranged in the circumferential direction are integrally molded by resin molding with a resin material and fixed to the motor casing 14. The iron core piece 311 can be made of, for example, an electromagnetic steel plate or an amorphous metal.

When a current flows through the coil 312 wound around the iron core piece 311 of the stator 31, the rotor 32 is given a rotational force by the magnetic field generated in the stator 31 and the rotor 32. The rotary shaft 12 rotates as the rotor 32 rotates.

When the iron core piece 311 is made of an amorphous metal, the loss is significantly lower and the magnetic permeability is higher than that of other magnetic materials, so that high motor efficiency can be obtained. On the other hand, amorphous metal is not suitable for processing such as punching because the metal itself has a high hardness and is brittle and is used with a relatively thin plate. In the axial gap type motor, the stator 31 can be configured by the iron core piece 311 on which fan-shaped (see FIG. 2) foil strips that are relatively easy to produce are laminated. Therefore, the axial gap type motor is suitable for use of amorphous metal because the stator 31 can be produced without punching a complicated shape.

On the surface 161 of the end bracket 16, an end surface 162a perpendicular to the axial direction of the rotary shaft 12 is formed in the shaft penetrating portion 162 of the rotary shaft 12, and the static elimination brush 60 is fixed to this end surface 162a.

FIG. 3A is a side view of the scroll compressor 100 shown in FIG. 1, and FIG. 3B is an enlarged view of the static elimination brush 60 shown in FIG. 3A and its peripheral portion. The static elimination brush 60 is, for example, a carbon brush, and as shown in FIG. 3B, the upper end surface is pressed by the screw 62 inserted into the bolt 61 in the end surface 162a of the shaft penetrating portion 162, so that the lower end surface Are pressed against the surface of the rotating shaft 12.

For example, when a current is passed through the coil 312 using an inverter power supply when driving a motor, when the rotating shaft 12 is rotated at high speed, a shaft voltage is generated in the rotating shaft 12. As shown in FIG. 1, the bearings such as the main bearing 33 and the anti-load bearing 34 are held by the flange 15 and the end bracket 16, and in these bearings, the bearing inner ring contacts the rotating shaft 12 and the bearing outer ring It is in contact with the flange 15 and the end bracket 16. Therefore, as described above, when an axial voltage is generated on the rotary shaft 12, a potential difference between the rotary shaft 12 and the flange 15 or the end bracket 16 is generated between the inner and outer rings of the bearing. When this potential difference exceeds the dielectric strength of the bearing oil film, the oil film dielectric breakdown causes a bearing current to flow, causing bearing electrolytic corrosion.

In the scroll compressor 100 according to the embodiment, as described above, the current generated in the rotating shaft 12 is applied to the surface of the rotating shaft 12 by contacting the discharging brush 60 and grounding the discharging brush 60. It is possible to reduce the axial voltage by discharging from the 61 and the screw 62 to the end bracket 16 and the motor casing 14. Therefore, the occurrence of bearing electrolytic corrosion can be suppressed. In addition to the bolts 61 and the screws 62, for example, a spring may be used to fix the static elimination brush 60.

Particularly in an axial gap type motor, since the facing area between the stator 31 and the rotor 32 is large, the electrostatic capacity tends to increase. Therefore, as compared with the radial gap type motor, for example, in the axial gap type motor, a higher shaft voltage is likely to be generated in the rotating shaft 12, and the occurrence of bearing electrolytic corrosion is more remarkable.

As described above, in the scroll compressor 100 according to the embodiment, the static elimination brush 60 fixed to the end bracket is in pressure contact with the rotary shaft 12, so that even if a high axial voltage is generated in the rotary shaft 12, this axial voltage Can be reduced and the occurrence of bearing electrolytic corrosion can be suppressed.

In the example shown in FIGS. 1 and 3, the static elimination brush 60 and the screw 62 fixing the static elimination brush 60 are provided so as to be exposed to the outside of the scroll compressor 100. Specifically, when the space 20 between the end bracket 16 and the cooling fan 13 is seen from the outer diameter side of the motor 10 and the cooling fan 13, the head of the screw 62 can be visually recognized. ..

In the example shown in FIG. 1 and FIG. 3, the distance D between the surface 161 of the end bracket 16 and the end surface 132A of the fan cover 132 ensures the amount of intake of the outside air necessary for generating cooling air in the cooling fan 13. The size is ensured, which is large enough to allow a tool such as a screwdriver to be inserted into the space 20 from the outside of the scroll compressor 100.

Therefore, for example, when removing the static elimination brush 60 from the end bracket 16 in order to replace or repair the static elimination brush 60, a tool such as a screwdriver is directly inserted into the space 20 from the outer diameter side of the motor 10 and the cooling fan 13. By performing an operation such as loosening the screw 62 exposed to the outside, the charge removal brush 60 can be easily removed without removing the end bracket 16 and the fan cover 132. Therefore, the maintainability of the static elimination brush 60 can be improved as compared with the configuration in which the static elimination brush 60 is installed in the motor casing 14 or the fan cover 132.

As shown in FIG. 1, the compression unit 110 has a fixed scroll 43 and an orbiting scroll 44 arranged to face the fixed scroll 43. The fixed scroll 43 and the orbiting scroll 44 are housed in the main body casing 41.

The main body casing 41 is a tubular body having openings at both ends, the fixed scroll 43 is attached to one opening, and the motor 10 is attached to the other opening.

In the fixed scroll 43 and the orbiting scroll 44, spiral wrap portions 43B and 44B are formed on the surfaces of the end plates 43A and 44A, respectively. A compression chamber 45 is formed by the wrap portion 43B of the fixed scroll 43 and the wrap portion 44B of the orbiting scroll 44 meshing with each other. Tip seals 43C and 44C are provided at the tips of the wrap portion 43B of the fixed scroll 43 and the wrap portion 44B of the orbiting scroll 44, respectively.

On the back surface of the orbiting scroll 44, an orbiting bearing 47 is provided on the boss portion 46. The eccentric portion 12a of the rotating shaft 12 is inserted into the orbiting bearing 47, and thus the eccentric portion 12a of the rotating shaft 12 is supported by the orbiting scroll 44.

The eccentric portion 12a of the rotary shaft 12 makes eccentric motion with the rotary motion of the rotary shaft 12. Therefore, when the rotating shaft 12 is rotationally driven by the motor 10, the orbiting scroll 44 connected to the eccentric portion 12a orbits.

The orbiting movement of the orbiting scroll 44 is continuously performed by canceling the eccentricity of the orbiting scroll 44 by the rotation of the counterweight 135 attached to the end of the rotating shaft 12.

When the orbiting scroll 44 orbits, the compression chamber 45 defined between the wrap portion 43B of the fixed scroll 43 and the wrap portion 44B of the orbiting scroll 44 is continuously reduced. As a result, the fluid introduced into the compression chamber 45 is compressed and the compressed air is discharged to the outside of the compression section 110. Although not shown, one of the plurality of compression chambers 45 serves as a fluid suction port, and one of the plurality of compression chambers 45 serves as a compressed fluid discharge port.

According to the scroll compressor 100 according to the embodiment described above, the static elimination brush 60 is fixedly installed on the surface 161 of the end bracket 16 so that the space 20 secured for inhalation of the outside air is effective. Can be utilized. As described above, most of the outside air that has flowed in from the space 20 is sucked through the suction port on the outer diameter side of the cooling fan 13, so that the region 21 on the inner diameter side of the space 20 contributes to the intake of the outside air. No, it is virtually dead space. According to the scroll compressor 100 of the embodiment, the static elimination brush 60 is fixedly installed on the surface 161 of the end bracket 16, so that the region 21 which is a dead space in the space 20 can be effectively used. Therefore, it is possible to suppress the adverse effects such as the failure due to the electrolytic corrosion of the bearing, and to reduce the size and space of the entire compressor.

Further, the space 20 between the end bracket 16 and the cooling fan 13 also allows the outside air to pass to some extent in the area 21 on the inner diameter side. Therefore, by installing the static elimination brush 60 in this region 21, the sliding surface of the static elimination brush 60 is cooled by the outside air. Therefore, the brush life of the static elimination brush 60 can be extended.

Further, according to the scroll compressor 100 according to the embodiment, even when a high axial voltage is generated on the rotating shaft 12, the static eliminating brush 60 can reduce the axial voltage. Therefore, with the axial gap type motor using the amorphous alloy for the stator 31, it is possible to obtain high motor efficiency, and it is possible to suppress adverse effects such as failure due to bearing electrolytic corrosion.

Further, in the scroll compressor 100 according to the embodiment, since the static elimination brush 60 is fixedly installed on the surface 161 of the end bracket 16, the counter weight 135 is provided at the end of the rotary shaft 12 on the cooling fan 13 side. Can be installed in Therefore, the weight of the counterweight 135 necessary to cancel the eccentricity of the rotary shaft 12 can be reduced, and the weight of the counterweight 135 can be reduced.

That is, in the conventional configuration in which the static elimination brush is installed at the end of the rotary shaft, the counter weight 135 cannot be installed at the end of the rotary shaft 12, and the counter weight 135 is located closer to the center than the end of the rotary shaft 12. Will need to be installed. In this case, the weight of the counterweight 135 necessary to cancel the eccentricity of the rotary shaft 12 becomes heavy.

Further, in the scroll compressor 100 according to the embodiment, since the static elimination brush 60 is fixedly installed on the surface 161 of the end bracket 16, the fan cover 132 is electrically connected to the static elimination brush 60 and the motor casing 14. There is no need. Therefore, a resin cover can be used as the fan cover 132, the manufacturing cost of the scroll compressor 100 can be reduced, and the scroll compressor 100 can be reduced in weight.

That is, in the conventional configuration in which the static elimination brush is provided in contact with the fan cover, it is necessary to use a metal fan cover, which increases the manufacturing cost.

In addition, in the scroll compressor 100 according to the embodiment, the fan cover 132 is not necessarily limited to the resin cover, and a metal cover may be used.

In the scroll compressor 100 according to the embodiment described above, the configuration in which the axial gap type is adopted as the motor 10 has been described as an example. However, the motor 10 is not limited to this, and it is also possible to use a motor having another configuration such as a radial gap type motor, for example.

100... Scroll compressor, 10... Motor, 110... Compressing part, 12... Rotating shaft, 12a... Eccentric part, 13... Cooling fan, 131... Rotating blades, 132... Fan cover, 132A... End face, 135... Counterweight, 14 ... Motor casing, 15... Flange, 16... End bracket, 161... Surface, 162... Shaft penetrating portion, 162a... End face, 20... Space, 21... Region, 31... Stator, 311... Iron core piece, 312... Coil, 32... Rotor, 321... Permanent magnet, 33... Main bearing, 34... Anti-load bearing, 41... Main body casing, 43... Fixed scroll, 44... Orbiting scroll, 43A, 44A... End plate, 43B, 44B... Spiral wrap portion, 43C , 44C... Tip seal, 45... Compression chamber, 46... Boss part, 47... Slewing bearing, 60... Static elimination brush, 61... Bolt, 62... Screw, D... Distance

Claims (5)

A rotor housed in the motor casing,
A stator housed in the motor casing to drive the rotor to rotate;
A rotating shaft that is held by a bearing and rotates integrally with the rotor;
An end bracket that penetrates one end of the rotating shaft and closes the motor casing,
A revolving scroll that supports the other end of the rotating shaft and that revolves by the rotation of the rotating shaft,
A fixed scroll arranged to face the orbiting scroll,
The end surface of the fan cover facing the end bracket is fixed to one end of the rotary shaft with a space provided between the end bracket and the end surface of the fan cover. A suction type cooling fan that sucks outside air from a suction port provided and generates cooling air for cooling the fixed scroll or the orbiting scroll inside the fan cover,
A static elimination brush fixed to the end bracket facing the cooling fan by a fixing member mounted in the radial direction with respect to the rotation shaft in a space secured by the space, and having one end in contact with the rotation shaft. A scroll compressor characterized in that The scroll compressor according to claim 1, wherein the static elimination brush and the fixing member are exposed to the outside in the space. The scroll compressor according to claim 1, wherein a counter weight is provided at an end of the rotating shaft on the cooling fan side. In the stator, a plurality of iron core pieces around which a coil is wound are arranged in the circumferential direction,
The scroll compressor according to claim 1, wherein the stator and the rotor are arranged to face each other in a direction parallel to the rotation axis with a gap therebetween. The scroll compressor according to claim 4, wherein the iron core piece is made of an amorphous metal.

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